curry@nsc.UUCP (Ray Curry) (04/16/86)
Riding style and the counter steering debate gets very emotional even by people who really know what they are doing based up years of successful competition. Witness the magazine debate between Kevin Cameron, one of the two most successfull motorcycle tuners/developers and Keith Code, racer, math teacher, motorcycle racing instructor and developer of the Superbike school. Having raced myself semi-professionally for seven years, in the Northwest, I have spent time in chassis development and am starting to due some real measurements for some computer simulation that I want to develop. My most emphatic urging is to not be so committed to a single belief in what makes a motorcycle go around corners. Because there is no single thing that does it. The thing that racers know and all that they know is that they counter steer and the bike turns. First some imperical data. Counter steering is the major force at speed that the rider exerts to cause the bike to lean. The bike does not start to turn until the lean is completed. The front wheel ends up turned into the turn while the turning is actually in progress. Weight balance, ie hanging off affects the turn radius because the inword force is the arc- tangent of the angle of lean of the center of gravity. This is the real physics of the situation. You can calculate it your self by knowing the the body is stable. Sum the weight, centripital force, and acceration. This is why a passenger without touching the driver or bars can impact turning radius. Just try going around a corner with a passenger sitting upright sometime. The forces that cause the lean and the forces that cause the turn are not the same although they can be related. While its true, gyroscopic effects are not appreaciable at slow speed, they do have an impact at high speed. When the very first streamliners ran at the salt flats, the drivers, without normal body weight control, noticed that the steering effects changed with speed. Slow, turn right to go right; 30 mph, turn left to go right; 200 up, turn right to go right. If you want to prove to yourself, counter steering and turning are related but not the same, take a single tire, lean it to one side, and give it a push. What happens? I appologize for the length of this article, but it is difficult to discuss all the inputs without a few words. I do have a model that I am developing that I will post to the net sometime later that descibes many of the forces envolved that cause the turning itself, but in the meantime, remember it really isn't important what makes the bike turn. It's the actions you take that by experience you have found work. The words I leave you with are that in biking as in any skill activity, the longer you do it and the better you are, the less likely you are to notice what you are doing right.